All,

I've been wondering: is there a way to do the "fan mod" (where you ground the wire coming out of the ECU harness for 2 min and then your fans stay on for 10 min after you shut off your car) in such a way as your fans come on instantly? I am sure I'm going to forget this from time to time and sitting in my car for ~2 min is kinda annoying.

Anyone? I'm aware of the "Disney" mod but I'm not looking to get that deep into the wiring system...

Does the wire go into the ECU? Or does it charge some capacitor in a relay somewhere? If so, could that relay be replaced?...

-ch

 

What's kind of strange is that I have done the "fan mod" but my fans come on instantly and they don't stay on for the 10min like they are supposed to. So it's basically a low speed fan on-off switch for me.

 

take a wire, tap into a fan relay, bring it to a two way spst switch , ground it , bada bing bada boom instant fanage

 

ISU: Weird. Do you have a '95 perhaps?

RX-7: Yeah, but I'm looking for the 10-min stay-on feature. I want a way to prime the post-shutdown routine without having to anticipate it by two minutes...

-ch

 

have you guys seen the hks fan controller

 

I've been wondering about this. Couldn't you just set up a relay to control the fan and use one of those dome light timers or something to send it a signal? Or set up some simple circute or even some simple kitchen timer where you wire it in a way so that it turns the fans off when the alarm goes off?

I may try the dome light thing since my jetta has a domelight with an integral timer built into it.

Just thinking out loud....

 

The 10 min stay on thing works, as long as you have the switch on for I think 2 min? or 1:30 seconds it will stay on for 10 min after the car is shut off.

 

Right--what I am looking for is something where I can turn the switch on and INSTANTLY the fans will come on and stay on for 10 min. after the car shuts down. I don't want to have to anticipate stopping the car by 1-2 minutes.

Really, no one has figured out how to do this? Where does the 10-minute time come from? Is this an ECU thing? Or is there a relay with a timer? Anyone?

-ch

 

I have the fan mod in my car. You don't have to try and guess the last 2 minutes. Just turn it on 5 minutes or more before you stop. If you are driving for less than two minutes, you don't need it anyway.

I don't know of a way to do what you want.

 

You could do it fairly easily using a turbo timer.. Instead of connecting the timer to the ignition to keep the car running, connect it to the fans directly. Then simply set the time you want.
When you switch off the car, instead of it idling away, it will start up the fans for the time specified.

You would need to connect up a relay to the turbo timer, so that it latches on until the timer runs out.

 

why do you want the fans on after it stops anyway? its just cooling the radiator.

 

No, it cools the whole engine by convection, Early engines often did not even have water pumps.

I use a Permacool fan switch and the fans stay on until the water temp goes down to ~150F

 

Or you could just hook it up as normal and turn on the A/C to run the fans.

 

if you dont want to have to wait in yoru drive way 2 minutes before the fans kick in. Keep the switch on all the time, I drive around at night w/ mine on just so I have som light in my car but when i get home and shut the car off the fans are always running, then I just shut the switch off and it goes into low fan mode.

 

You are a nut. What have you been smoking?

Water does not circulate by itself

 

Calling prople names does not promote learning by anyone.

Hot water rises just like (your) hot air. The hot air in the engine rises toward the top and flows into the upper rad hose. As the water in the radiator cools it sinks toward the bottom of the radiator and being slightly denser, desplaces the warmer water in the engine.

ITS CALLED CONVECTION !

Did you sleep through 7th grade science class ? We had a four cylinder water cooled generator that used this principal alone to provide water circulation It had no water pump. The Ford Model-T had no water pump and used convection.

 

Your mistake is in thinking a controlled experiment or the Model T relates directly to the particular topic here at hand with the FD. Whether or not anyone understands convection has no basis on this problem as anybody with a temp gauge can draw their own conclusions as to whether this is true in the FD's case after the engine is shut down.

I am glad you enjoyed the 7th grade. Apparently you did so well in science class that you cannot spell. I am sorry to hear you think you are a "prople" and that cooler water "desplaces" warmer water. I hope you are either still in the 7th grade or in fact did not go to school in Texas

 

I will be the first to admit I didn't know the Model T used convection cooling. But understanding convection, I bet the following are all true of the Model T:

The cooling system was not pressurized.

There was no thermostat in the cooling system.

The radiator was higher than the majority of the engine block.

The radiator was very large.

The radiator was nearly upright.

The overall coolant capacity was very large.

The radiator held much more coolant than the block/hoses.

Again, I am just guessing but given those (or most of those) properties I think the Model T could have been cooled just fine. Now as for the FD:

The cooling system is pressurized.

There is a thermostat in the cooling system.

The radiator is lower than the majority of the engine block.

The radiator is small.

The radiator is horizontal.

The overall coolant capacity is not large.

The radiator holds much less coolant than block/hoses.

Given these personally perceived conflicts with the properties required for convection cooling to occur in an automobile it is my personal opinon that convection cooling at best is horribly inefficient in an FD, and at worst does not happen at all.